Sidewall of a tire



FIG. 1 is a top plan view of a sidewall of a tire, showing my new design; and,

FIG. 2 is an edge elevational view thereof, all other edge elevational views being identical thereto.

The broken line showing of a tire is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a sidewall of a tire, as shown and described. 